Grinding machine



March 1929- J. N. HEALD ET AL 1,705,114

GRINDING. MACHINE Filed March 31, 1924 ,z'i'avanzj'ori JEzInes l iJ-L'eild Patented Mar. 12, 1929.

UNITED STATES PATENT OFFICE.

JAMES N. HEALD AND RAY D. HUBBELL, OF WORCESTER, MASSACHUSETTS,ASSIGNORS TO TION OF MASSACHUSETTS.

THE HEALD MACHINE COMPANY, OF WORCESTER, MASSACHUSETTS, A CORPORA-GRINDING MACHINE.

Application filed March 31, 1924. Serial No. 703,097.

The present invention relates to grinding machines, and contemplatescertain unprovements and refinements in the reciprocatory table controlmechanism disclosed in the co- )ending application of Drake and Guild,erial No. 685,577, filed January 11, 1924,- the principal object herelnbelng tomake the wheel dressing and trulng operation in a grindingmachine wholly automatic from startto finish, once said operation hasbeen inaugurated by the machine operator. The several features'of theinventionby wh ch the above and other objects are attained are fully setforth hereinafter, reference being had to the accompanying drawings, inwhich- 1 Fig. 1 is a View in side elevation of so much of a grindingmachine, here shown as of the internal type, as is necessary to disclosethe invention.

Figs. 2, 3 and 4 are sectlonal views on the lines 2-2, 3-3 and 44,respectively, of Fig. 1. I

Fig. 5 is an enlarged detall v1ew of a latching mechanism forming partof the invention.

Like reference characters refer to like parts in the different figures.

Referring first to Fig. 1, the invention is here shown, by way ofexample, in connection with the reciprocatory table or carriage 1 of thegrinding machine. In such a machine, either the grinding wheel, or thework to be ground, may be carried by the table 1, the reciprocations ofthe latter being utilized in either case to produce a relativetraversing movement between the grinding wheel and the work. As hereshown the table 1 supports and carries a wheel head 2 of ordinaryconstruction, the work sup orting head 3 being carried by a bridge 4 wich spans the slideways provided by the machine frame for the movementof the table 1. Back and forth movement of said table 1, to cause therotating grinding wheel to make the required traverse of the rotatingwork piece 6, may be imparted in any well known manner, as for instance,by the use of the fluid pressure controlling and reversing mechanismthat forms the subjectmatter of the copending application of Heald andGuild, Serial No. 629,882, filed April 4, 1923. Such mechanism, or itsequivalent, forms no part of the present invention and a detaileddescription thereof is therefore unnecessary; it is sufficient to note,for the purposes of the present application, that the type of driveadopted for the actuation of the table 1, be it hydraulic drive, or geardrive, or any other type, procures the reversal of said table at eachend of the latters working stroke by the use of spaced adjustabletabledogs 7 and 8, adaptd to alternately engage and move an interposed member9, whose position controls the direction of table travel.

1n the normal operation of the machine, with the grinding wheel 5 incontact with the work piece 6, the table 1 will be reversed at eachsuccessiveengagement of the member 9 by the dogs 7 and 8, which dogs,obviously, are spaced apart on said table a distance correspondingsubstantially to the working slroke of the grinding wheel 5, i. e., thelengthof the hole in the work piece 6. As disclosed in the aforesaidapplication of Drake and Guild, the dog 8 herein is pivoted at 10 to itscarrying block 11, so that its other or striking end can be elevated byany suitable means, at the will of an operator; this elevation causesthe dog 8 to clear the top of member 9, and thus prevents, when desired,the reversal of the table 1 .which would otherwise and normally takeplace at its right hand limit of working rcciprocation,the right handmovement being continued so as to withdraw the grinding wheel altogetherfrom the working zone,

to permit the hole in the work piece 6 to be sized or plugged, or topermit the re moval of said work piece and the introduction of a.newwork piece. This withdrawal movement preferably takes place at highspeed; due to theengagement of a bar 13, attached to block 11, with aroller 14 on an arm 15, in the manner described in the aforesaidcopending application of Heald and Guild. The mechanism as so fardescribed forms no part of our present invention, and a further detailedreference thereto is therefore unnecessary.

In order to subject the grinding Wheel 5 to the action of a dressing ortruing device such as shown at 16, Fig. 1, the carrying-block 11 of dog8, instead ofbeing secured directl to the table 1, as is the case withthe bloc 17 of dog 7, is allowed, under certain conditions, to slidefreely longitudinally of said. table. Under normal conditions, when thetable 1 is making its usual working reciprocations, to traverse thegrinding wheel back and forth within the work piece, the block -11 ofdog 8 is held in definite spaced relation to a block 18, which latter,the same as the block 17 of dog 7, is adapted to be se cured by theusual locking devices 19 in any desired position of adjustmentlongitudinally of the table 1. This connection between the blocks 11 and18 is here shown in the form of a latch lever 20, which is pivoted at 21to the block 18, and which has near its free end a shoulder 22 and a pin23, said shoulder 22 cooperating normally with an abutment 24 on block11, to hold said block a predetermined distance away from block 18, andsaid pin cooperating with the right hand edge of block 11 to limit thedistance by which said blocks 18 and 11 can be separated.

As shown in Fig. 5, the latch member 20, when operative, rests bygravity on the flattened surface of a rocking pin 25, which is looselyjournaled in the block 11, and which has a handle 26 that allows theoperator to swing it through a limited are, thereby to raise the latch20 and thus free the shoulder 22 from the abutment 24. When this isdone, the block 11 is no longer rigidly connected with the block 18, buton the contrary, said block 11 is free to slide to the left on table 1as said table moves to the right; in other words, under theseconditions,

on the right hand movement of table 1, the dog 8 will bear withouteffect against ID0111- ber 9, and thus the right hand movement of saidtable will be prolonged beyond the usual reciprocatory working path, sothat the grinding wheel 5 will be carried past the dresser 16. Thisaugmented right hand movement of the table 1 causes the block 11 toslide, relative to said table, to the left, owing to the obstructionwhich the member 9 imposes against the dog 8; finally the adjustingscrew 8' of block 11 is brought up against a projection 27 on block 18,whereupon the solid backing thus afiorded for the block 11 enables thedog 8 to shift the member 9. This procures reversal of the table 1, andthe left hand movement thus inaugurated is caused to restore the partsautomatically to normal position in the following manner A member 28,secured rigidly to the frame of the machine, carries a fiat spring 29,to the free end of which is secured an upwardly projecting lug 30, forcooperation with the block 11. In the normal grinding operation of themachine, when the blocks 18 and 11 are positively connected for movementin unison by the latch 20, such lug offers no effective obstruction tothe back and forth travel of the block 1]. in unison with the table 1,it being obvious that when said block, under these conditions, strikeseither bevelled side of said lug, the latter will be wedged downwardly,the spring 29 yielding sufliciently to allow the block to pass over thelug. However, when the block 11 has been freed from the block 18, asabove described, to augment the right hand movement of the table 1, theensuing reversal of said movement, with the block 11 still free, findsthe lug 30 in position to contact with the left hand side of said block,and under these conditions, said lug offers an obstruction sufficient toovercome whatever friction there may be tending to cause the block 11 tomove to the left with the table. The block 11 being thus heldstationary, while the table 1 and block 18 continue to move to the left,the latch member 20 finally resumes its normal position relative to theblock 11, when the pin 23 again engages the right hand edge of saidblock; this allows the shoulder 22 of the latch member 20 to drop behindthe abutment 21, and the parts being thus automatically restored tonormal position, the block 11 will'move in unison with the block 18 andforce the lug 30 out of its way, as above described. It is to beunderstood that in this operation of dressing the grinding wheel 5, theaugmented table movement ol limited amplitude takes place at the usualworking speed, i. e., without the increase in speed that occurs when thefull withdrawal movement of the table is etl'ected. This is because thebar 13 is secured to the block 11, and hence when said block slips tothe left as above described in the wheel dressing operation, the bar 13is prevented from coming into contact with the roller 14.

- lVc claim,

1. ln apparatus of the class described, a reciprocatory table, a membershiftable in opposite directions'to procure the reversals in themovement of said table, adjustable stops carried by said table forengaging and shifting said member, one of said stops being releasable soas to be movable longitudinally to temporarily increase the travel ofsaid table in one direction, said stop ultimately acting to reverse saidtable, and means for automatically restoring said stop to normalposition.

2. In apparatus of the class described, a reciprocatory table, a membershiftable in opposite directions to procure the reversals in themovement of said table, a pair of stops carried by said table forengaging and shifting said member, a block adjustably secured to saidtable, one of said stops being adjustably secured to said table and theother being held in spaced relation to said block, means for releasingsaid last mentioned stop from said block, to permit an increase of tabletravel in one direction, and means for automatically restoring said lastmentioned stop to normal position.

3. In a grinding machine, a table carrying a grinding wheel, and adaptedto resaid dresser, an adjustable member on saidtable, a connectionholding said stop in spaced relation to said member, means fordisengaging the connection topermit traverse of said wheel by saiddresser, and means for automatically restorlng the spaced relation andreengaging the connection to again hold said stop and said member inspaced relation.

4. In a grinding machine, a reciprocatory table, a member shit'table inopposite directionsto procure the reversals in the movement of saidtable, a pair of stops carried by said table for engaging and shiftingsaid member in the normal working movements of said table, means forincreasing the working traverse of said table by releasing one of saidstops from said table, said stop ultimately acting to reverse saidtable, and means operable by the travel of said table for restoring saidstop to normal position.

5. In a grinding machine, a reciprocating table, a shit'table member, astop carried by said table and operable on said shiftable member tolimit the table movement in one direction, means for releasing said stopto increase, by a predetermined amount, the reciprocatory traverse ofsaid table in said direction, means cngageable with said stop to bringit to rest, making it effective again on said shittable member, afterthe table has moved said predetermined amount, and means operable on thereverse movement of said table to return said stop to normal position.

G. In a grinding machine, a grinding wheel, adjustable means forprocuring limited reciprocatory working traverse between said wheel andthe work to be ground in the normal operation of said machine, agrinding wheel dresser, means operable without destroying the adjustmentof said adjustable means to increase the relative movement, in onedirection, between said wheel and said work, thereby to subject saidwheel, when desired, to the action of said dresser, and means broughtinto action after said increased movement for automaticallyreestablishing said limited reciprocatory working traverse.

7. In a grinding machine, a rotary grinding wheel and a rotary workholding device, a table on which one of said parts is carried, saidtable, in the normal operation of the machine, having a predeterminedreciprocatory traverse, a grinding wheel dresser out of contact withsaid wheel during said normal working traverse of said table, means fortemporarily increasing the amplitude of table traverse to subject saidwheel to the action of said dresser, and means brought into action afterthe increased amplitude of table movement for automatically procuringsaid resumption of normal working table traverse.

8. In a grinding machine, a grinding wheel, means for procuring apredetermined reciprocatory working traverse between said wheel and thework to be ground in the normal operation of said machine, a grindingwheel dresser, means for increasing the traverse between said wheel andthe work by a predetermined amount in one direction, to subject saidwheel to the action of said dresser, and means brought into action aftersuch increased traverse for automatically procuring the resumption ofthe normal reciprocatory working traverse between said wheel and thework to be ground.

9. In a grinding machine, a grinding wheel, adjustable means forprocuring limited reciprocatory working traverse between said wheel andthe work to be ground in the normal operation of said machine, agrinding wheel dresser, means operable without destroying theadjustmentof said adjustable means to increase the relative movement, inone direction, between said wheel and said work, thereby to subject saidwheel, when desired, to the action of said dresser, and means forautomatically reestablishing said limited reciprocatory movement after asingle increased relative movement.

10. In a grinding machine, a reciprocatory table, a stop carried by saidtable, latching means normally holding said stop fixed with respect tosaid table, a fixed member in the path of said step adapted to yieldwhen said stop is held by said latching means, means for releasi saidlatching means, said member being t en adapted to hold said sto andallow it to move relatively to said ta le, 2. second stop fixed to saidtable to limit rela tive movement of said first stop along said table,said member being operable upon the reversal of said table, after saidrelative movement, to hold said first stop stationary until saidlatching means is again made operative.

Dated this 29th day of February, 1924.

JAMES N. HEALD. RAY D. HUBBELL.

